Conventionally, inkjet printing apparatuses perform a printing operation by prompting a head to discharge inks on a recording medium while reciprocating the head. Some of the inkjet printing apparatuses use inks of ultraviolet curing type as printing inks. The inks of ultraviolet curing type are curable by being irradiated with ultraviolet light.
As described in Patent Literature 1, a recording medium having a print object printed thereon with inks of ultraviolet curing type may have its outermost surface coated with a clear ink to improve in glossiness. In the printing method described in Patent Literature 1, an overprint layer is formed on a tack-dry color ink layer and left standing for a given period of time. Then, the surface of the overprint layer is flattened, and the color ink layer and the overprint layer are then cured.